var queneExec = function(fn,contex,t) {
	this._fn = fn;
	this._contex = contex || window;
	this._t = (typeof t == 'undefined')? t : 0;
	this._quene = [];
	this._running = false;
};

queneExec.prototype = {
	add : function (elem){
		if(elem){
			this._quene.push(elem);
			if(!this._running ){
				this._exec();
			}
		}
		return this;
	},
	_exec : function(){
		var t = this,
			item;
		if(this._quene.length > 0){
			t._fn.call( t.contex, t._quene.shift() );
			t._running = true;
			setTimeout(function(){
				t._exec();
			}, t._t);
		}else{
			t._running = false;
		}
	}
};